Electromagnetic switch.



C. W. COLEMAN & A. V. T. DAY.

ELECTROMAGNETIC SWITCH.

APPLlcATloN H ED1uLY6.190S,

1,168,068. lmmml im. 7, 1915.

2 SHEETSSHEET l.

C. W. COLEMAN I A. V. T. DAY.

ELECTROIVIAGNETIC SWITCH.

APPLICATION FILED IULYG, I908.

1,163,068. Patented Dec. 7, 1915.

2 SHEETS-SHEET 2.

UNITED STATES PATENT oEEIoE.

CLARENCE W. COLEMAN,

ELECTROMAGNETIC SWITCH.

specification of Letters Parent.

Patented Dec. 7, 1915.

Application led July 6, 1908. Serial No. 442,021.

the following is a specification, reference beings, forming part thereof.

` Our invention relates to electrically controllable railway traffic-controlling apparatus and systems, and particularly to that ing hadtherein to the accompanying drawclass of traflic-controlling apparatus and systems wherein the railroad trafic is controlled by the display of visual signals, such, for instance, as semaphores.

Still more particularly our, invention relates to the electro-responsive means or electric relays employed in such traiiic-control'- ling or signaling systems.

One object of our invention is to provide an electro-responsive device or relay which will be sensitively responsive to comparatively weak electrical energization. I

In that embodiment ofl oui` invention which we have illustrated in the accompanying drawings, `the electro-responsive device is a relay-that is to say, the electroresponsive device in `this particular embodiment of our invention is employed to control electrical circuits which, in turn, control the signals. But the electro-responsive device of our invention, -in its broader aspect, need not necessarily be a. relay, since, 1n lieu of controlling electric circuits, it may be employed to directly control or actuate a vlsual or audible signal or other trahie-controlling device. In either event, this feature of our invention relates particularly toy polarized signal-controlling relays or electro-responsive devices, that is tol say, relays or electro-responsive devices the actuation of which depends upon the polarity or dlrec- `tion of the current which actuates them.

This feature of our. invention relates broadly to such polarizeddevices, whether the same are to be actuatediby a uni-directional current or by an alternatin current; and when our signal-controlling e ectro-responslve device or relay is to-be actuated by a uni-d1- rectional current, its actuation will vdepend Y cuts radially through the upon the continued polarity or direction of the current, and when it is to be actuated by an alternating current, its actuation will depend upon the instantaneous direction of thatalternating current, so that a reversal of the alternatingv current, in other words, a change of 180' egrees in the phase, will 'affect the response of the device.

- The signal-controllin electro-responsive device or relay of our lnvention comprises two coacting coils which conduct electric currents in such a manner that the magnetic eld produced by one coil acts upon the other coil to eifect a movement of one coil relative to the field ofthe other, and our invention partly consists in corganizing these two coils together with their magnetic circuits in a. certain manner which attains of the colls, so

the most eiiicient coaction that the device will respond' when the current in `one of the coils is comparatively Weak. This corganization consists in such a relative disposition of the coils thatthe magnetic field from one lcoil, which will preferably be the stationary coil or eld coil, enters the second coil axially and then conductors thereof, so that, when this second coil is the movable coil-or armature coil, all sides thereof will be forced by the field in one direction (when the armature coil is supplied with current from an extraneous source, as it is in our invention), thus permittin the armature coil to Vbe hung upon a pivota axis entirely outside of the coil itself, and also `permitting the field to cut Vvthe armature coil at substantially all points so that there is very little idle wire in the armature coil which is not subjected to motive force from the field.

As a still further feature-of invention, one coil, which' will preferably act as the field coil, will be disposed, preferably in two sections, in asymmetrical relation to the plane of the Second coil or armature coil, so that the field will enter the armature coil axially and in opposite directions from both sides if theY armature coil,'thus producing Within the armature coil a consequent pole from which the lines of force will radiate and cut the conductors of 'the armature coil throughout substantially its entire circumference.

We will now describe the embodiment of our invention illustrated in the accompanying drawings, and will thereafter point out our invention in claims.

Figure l is a rear elevation of a polarized electric relay, and is a right-hand view of Fig. 2 after removing the glass case Lil and after cutting away a portion of one of the pole pieces and a portion of the field coil. Fig 2 is a vertical section on line :1cx, Fig. l, looking toward the left side of that figure. Fig. 3 is a diagrammatic perspective representation of the electric circuits and connections in the relay, showing diagrammatically an application of the relay to electric signaling.

rlhe illustrated embodiment of our invention is a relay comprising a magnetic field, an armature coil located in and controlled by the field, and contact fingers moved and controlled by the armature coil. The magnetic field is produced by a field member comprising a magnetic circuit of soft iron, and a winding for energizing the magnetic circuit. rl`he magnetic circuit comprises two members, each of which has a core piece l and a cylindrical shell portion 2 connected by a disk-shaped yoke portion 3, the core, shell and yoke being integral; and the two members are placed with theircore portions in contact so as to form a single core connected at its ends with the yoke portions.-

Between the shell portions 2 are two slottedannular core pieces fl in magnetic contact with each other and with the shell portions. The slotted-annular core pieces 4 are slotted or cut away to make room for the cross-over wires 12 and 13, which cross from either side to the other side of these core pieces as will appear more fully hereinafter, and also to make room forthe pendant arm 8, which carries the armature coil 7.- Each of the aforesaid integral pieces, including a shell, yoke and core, is cut with a slot 43 extending diametrically from the upper side of the shell entirely through the core piece l, this slot being provided to avoid eddy currents when the field is energized by periodic currents.

The winding by which the eld is energized comprises a coil in two sections 5 substantially surrounding the ends of the core. rlhese sections of coil are so connected that the current flows in them in opposite rotative directions about the anis of the coil, and this results inthe production of consequent poles between the coil sections, one pole being at the center of the core, while the other pole is at the inner surface of the annular pole pieces 4, the magnetic circuit being thus from the middle of the core to its ends, through the yokes 3, back to the center of the shell, and inward through pole pieces 4 and thence across the narrow air gap between the pole pieces and the core.

rl`he field member above described creates incense a powerful field of magnetic lines of force radiating .from the center of the core to the annular pole pieces 4 and concentrated in a plane substantially normal to the core at the middle thereof. The eld member is mounted in a recess in a 'metal plate 6 forming the front of the relay and the base upon which the several members of the relay are mounted.

The armature member cooperating with the field member above described comprises a. coil 7 surrounding the core and lyingnormally in the central plane of the field. This coil is closely embraced at all points by the poles of the field, and when energized by a current it tends strongly to move across the plane of magnetic flux toward one end or the other of the core, according to the direction of the current in the armature coil. To permit the coil to move in this mannerit is mounted on the pendant arm 3' which passes through an enlargement of the aforedescribed slot in the upper portion `of the shell, and has its axis pin 4:0 pivoted upon pivot screws 9 mounted on the base 6. The movements of the armature may be utilized in various ways according to the purpose for which the relay is employed, and in the illustrated relay it is utilized to move and control two contact fingers 1l mounted on lugs on the arm 8, and controlling electric circuits.

lt will be apparent that a field coil, consisting of a single'section 5, might be used to produce the concentric polesA between which the armature coil is suspended, but such an arrangement suffers from the inductive effect of the field coil on the -armature coil when the field coil is energized with alternating or periodic current. The relay maybe used with constant currents, but it is particularly designed and adapted for use with alternating or periodic currents, the currents in the eld and the armature being of the same periodicity and the armature being moved in one direction or the other according to the relative instantanepus directions of currents in the field coil and armature. ln such a use of our relay with alternating or periodic currents, the field eX- citing current, if it were passed only through a simple coil such as a single one of the field sections 5, would have a powerful inductive effect on the armature coil when the latter is on closed circuit; but if the field winding be symmetrically disposed with relation to the plane of the armature coil, it has no such eect on the latter coil. When periodic current is employed to excite the field, a field coil of a single section on only one side of the armature coil, or a field coil otherwise non-symmetrically disposed with relation to the armature coil, would produce a magnetic ux, a great portion of which would pass through and be linked with the armature coil soas to induce a conslderable secondary electro-motlve force therein to interfere with the electro-motive force from an extraneous source intended to operate the relays. Another effect of this secondary electro-motive force in the armature coil would be to induce a considerable current therein when the armature coil is i short-circuited, thus producing false `movements of the .armature coil when shortcircuited.' This secondary electro-motive force in the armature coil -will disappear when all the field flux entering. the coil in one direction is counterbalanced by an equal f the field coil, theinductive effects of the latter are neutralized by each other, and there is no unbalanced inductlve effect on the armature; and the movement of the armature may be so slight that it will at no time be sutJected to an unbalanced inductive action of the field sufficient to interfere with its proper response to currents from an extraneous source, although when the armature coilis short-circuited, for instance by a railway vehicle on a railway track, so much current as may be induced in thearmature coil by inductive action of the fields when the armature coil is displaced from neutral position, will be highly advantageous in its tendency to move the armature coil back to neutral'position. This tendency exists because when the armature is nearer to one field coil than to the other,the flux from the nearer field coil induces in the armature coila current tending to repel the armature coil until it cornes to the neutral position where the inductive actions of the two field coils upon it are balanced.

To avoid the disadvantageous effect of a short-circuit or break in the field winding, -the winding is arranged in the novel manner diagrammatically illustrated in Fig. 3, wherein the vsections -5 are not wound as separate coils and then connected in series or parallel, but are wound with one wire which crosses from one Section to the other at each-turn. Thus, in the diagram, the wire, starting at the left-hand section` 5, takes one turn Itherein, then passes across at 12 to the right-hand section, where it takes a single turn, and then passes back at 13 to the left-hand section, and so on until the coil is completed in two sections. The

pole pieces 4: are cut away at 12 and 13 to permit the transverse passage of the crossover wires of the winding.

By the above-described construction, vone coil of two sections is produced, but the arrangement is such that any short-circuit which may occur will have the effect of cutting out a substantially equal number of turns in both sections of the field coil, so that the effect of the field coil on the arma.- ture will be diminished, but not unbalanced, and there will be no tendency due to the short-circuit to move thel armature from neutral position. Also, a break at any point 1n the wire of the field coilvwill cut out both its sections equally.

The field winding is connected, by wires 14, with binding posts 15 mounted in grooved blocks 1-6 of insulating material. The armature coil is connected, by flexible Wires 17, with binding posts 18. A counterweight 19, adjustably mounted on a threaded stem 21 on the upper end of arm 8 balances the weight below the pivotal supports' of the arm. The contact fingers 1 are mounted on insulating blocks 22 on the backgof the lugs which extend from the arm 8, and the contact fingers are provided with contact springs 23. Two fixed contacts are provided for each` contact finger. Fixed contacts 24 are engaged when the armature moves backward. These contacts 'are mounted on blocks 25 of insulating material and are connected with binding posts 26. Fixed contacts 27 are engaged when the armature moves in the opposite direction, and these contacts are mounted on a block 28 of insulating material and connected with binding posts 29. Flexible wires 31 connect the contact fingers with binding posts Owing to the powerful form of field used in this relay and to the manner in which the armature coilis arranged and moves with relation to the field, the relay is very sens1t1ve in its .operation and is adapted for use in connection with comparatively feeble currents, such as occur in some systems of electric signaling in which inductive effects of track circuits are employed. Fig. 3 shows an application of the relay to a signal system, the relay being arranged to control selectively the home and distant signals. Here the field coil 5 is constantly energized by a transformer 33 connected with a suitable transmission line 47. The home and distant signals 35 and 36 are controlled by suitable electric mechanism connected, through a common wire 37, with a battery 38. The local signal circuits are completed through contact fingers 11 and the contacts 24 and 27. The home signal is connected with both fixed contacts of one contact finger, while the distant signal is connected with only the contact 27 of the other contact finger. The armature coil is connected with a track coil Olaid between the track rails and close to the rails so that current flowing in the rails will induce secondary current in the track coil, to be transmitted to the armature coil of the relay. The current in the track rails is produced by a transformer 46 fed from the same transmission line 47 which feeds the relay field through the transformer 33. Current Hows from the4 transformer 46 through a pole-changer 45l to the track rails 49 and thence vthrough the track rails around the track coil 50 and through the cross-bond 5i. Thus is induced in the track `coil and the relay armature an alternating current having the same frequency as the alternating current in the relay eld, since both currents are derived from the Same generator 48.

l:Viren there is a train on the section of track extending from A to ld, for example a train in the position or the arrow 44, the wheels and axles of the train will shortcircuit the current from the transformer 4G so that the track coil 50 and relay armature cannot be energized at all. When the armature is not energized, the contact ngers are in neutral position and both signals are set at danger. 'When the train has passed out of the section, the current transmitted through the'track rails and track coil will move the armature in one direction, whereby the home signalalone is cleared; and when the track is cleared still further ahead, the pole-changer 45 is reversed by any suitable means, automatic or manual, whereupon the armature moves in the other direction, in response to a current of opposite phase, whereby both signals are cleared. ln some cases it may be more convenient' to energize the armature coil constantly, while operating the relay by variations in the current in the ield. 'lhe members designated herein as iield and armature are interchangeable in their functions, and either member may be lined and the other relatively movable.

lt will be apparent that a polarized in strument constructed in accordance with this invention may be used for purposes other than the control of electric circuits;

as, for example, to directly operate Visual or audible signals, and various other modiications may be made in the embodiment of' my invention described herein and illustrated in the accompanying drawings within the nature and scope of the invention as defined in the following claims.

We claim:

l. A polarized electric signal-controlling or traiiic-controlling instrument having a iield member comprising a single winding arranged to induce a :field orn radial magnetic lines of force concentrated substantially in a plane, and a cooperating member comprising a coil lying normally in said plane in non-inductive relation to said ield, said members being relatively movable in a direction substantially normal to said plane in response to current variations.

2. A polarized electric signal-controlling or tratlic-controlling instrument having a.

field member comprising a core and a single winding thereon :formed to create a iield of radial lines' of magnetic `torce substantially concentrated in a plane bisecting the winding, and a cooperating member comprising a coil lying normally in said plane, said members being relatively movable in a direction substantially normal to said plane.

3. A polarized electric relay having a iield member comprising a winding consisting ot two., sections'with portions of the two sections alternately connected in series, and a cooperating second member comprising a coil lying between the sections of the lield winding, said members being relatively movable in a direction substantially normal to the plane of the coil of the second mem- 

